Draft capability entry (reuse-surface REUSE-WP-0017-T04, cohort 3)

Honest first-pass maturity vector grounded in README/docs/tests present
in this repo; no invented evidence. Flagged for human review before
publish. See reuse-surface history/2026-07-06-coverage-classification.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

registry/indexes/capabilities.yaml

@@ -1,4 +1,20 @@
 version: 1
-updated: '2026-06-16'
+updated: '2026-07-06'
 domain: helix_forge
-capabilities: []
+capabilities:
+- id: capability.graph.nbgm-spec
+  name: Network-Based Graph Model (NBGM) Specification
+  summary: Generic system and versioned protocol specification for exploring dependency structures as
+    network-based graph models (NBGM), unifying entity/relationship inspection and reasoning across arbitrary
+    domains.
+  vector: D2 / A0 / C1 / R0
+  domain: infotech
+  status: draft
+  owner: vantage-point
+  path: registry/capabilities/capability.graph.nbgm-spec.md
+  tags:
+  - graph
+  - nbgm
+  - specification
+  consumption_modes:
+  - informational (specification only)